Imaging devices that capture images have become smaller in size, and are now being used for various purposes.
In recent years, vehicles with driving support functions have become common. With the driving support functions, a scenery in front of the vehicle is captured, and the lane on which the vehicle is running, the vehicle running in front of the vehicle, a pedestrian rushing toward the lane, and the like are recognized in accordance with the captured image. Danger can be avoided in this manner.
In an imaging device as one of such functions, however, erroneous detection is performed when there is a failure. As a result, appropriate driving support cannot be provided. Therefore, there is a possibility that danger might not be avoided with the driving support.
For this reason, an imaging device for vehicles is required to have a function to detect a failure during operation of an analog circuit, according to ISO 26262 (an international standard for functional safety of electrical and/or electronic systems in production automobiles).
While there is such a requirement, a technique for detecting a failure related to disconnection of a horizontal signal line in an imaging device has been suggested (see Patent Documents 1 and 2).